Method of and apparatus for cleaning gases



F. R. McGEE AND A. F. NESBIT.

METHOD OF AND APPARATUS FOR CLEANING GASES.

APPLICATION FILED MAY 13. 1918.

1,372,711 0 Patented; Mar. 29, 1921.

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METHOD OF AND APPARATUS FOR CLEANING GASES.

APPLICATION FILED MAY I3, 1918.

I Patented Mar. 29, 1921,

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UNITED STATES smear ossica.

FRANK R. MCGEE, 0F STEUBENVILLE, OHIO, AND ARTHUR F. NESBIT, 0F WILKINS- BURG, PENNSYLVANIA METHOD OF AND APPARATUS FOR CLEANING GASES.

Specification of Letters Patent.

Patented Mar. 29, 1921.

Application filed may 13, 1918. Serial No. 234,289.

T 0 all whom it may concern:

Be it known that we, FRANK R.- MOGEE and ARTHUR F. N ESBIT, both citizens of the United States, and residents of Steubenville, in the county of Jefferson and State of Ohio,

and Wilkinsburg, in the county of Allegheny and State of Pennsylvania, respectively, have invented certain new and useful Improvements in Methods of and Apparatus for Cleaning Gases, of which the following is a specification.

Our invention relates generally to the cleaning of gases, and while not restricted to such uses, relates more particularly to the separation and removal of dust or tar or similar finely divided solids and liquids or semi-liquids from gases such as those evolved in the operation of blast furnaces, by-product coke ovens, gas producers and the products of combustion from cement kilns, steam boilers, metallurgical furnaces, and the like.

One object of this invention is the provision of a novel method of cleaning gases employing a combination of mechanical and electrical forces, and adapted to separate the gases from the impurities carried in suspension therein and segregate the cleaned gases.

Another object of our invention is to provide apparatus for cleaning gases having novel means whereby impurities present in the gases are separated from the gases and are trapped or isolated in a rapid, cheap and effective manner.

' A further object of our invention is the provision of a gas cleaner having the novel constructions, arrangements and combination of parts, shown in the drawings and to be described in detail hereinafter and particularly pointed out in the appended claims;

Referring now to the drawings forming part of this specification, F 'igurel is a sectional elevation showing a mechano-electrical gas cleaner embodying our invention and adapted for use in cleaning gases by the method forming a novel feature of our invention.

Fig. 2 is a sectional plan of the apparatus shown in Fig. 1, the section being taken on the line II-II of Fig. 1.

Fig. 3 is a sectional elevation on an enlarged scale, showing details in the construction of the gas cleaner.

Fig. 4 is a sectional plan on a largerscale,

showing details in they construction of the centrifugal headers forming part of our improved apparatus. 1

Fig. 5 is a plan showing details in the construction of the active electrode forming part of the apparatus of Figs. 1, 2, and 3.

F1g. 6 is a plan similar to that shown in Fig. 5, illustrating a modified form of active electrode.

Fig. 7 is a plan showing a'development of the curved vanes on the peripher of the centrlfugal headers forming part oi apparatus embodying our invention, the circumference of the headers equaling the distance between the lines X-X of Fig. 7

In the accompanying drawings, the numeral 2- designates the outer metal shell of the gas cleaner, which is cylindrical in cross section and has frusto-conical ends'3 and 4. The upper end 3 of the shell 2 is closed by a head 5 Which also forms the bottom of the insulator chamber A, this chamber having a cylindrical side wall 6 and a top 7.

The shell 2 is provided with a partition 8 near its upper end which separates the interior of the shell into a gas distributing chamber B and impurity collecting chamber C. and a series of radial branches 9 form inlets connecting the distributing chamber B with the annular gas conduit 10 which encircles the upper end of the shell 2 and conducts the gases to be cleaned to the chamber B. The annular conduit 10 is connected to one end of a gas supply main (not shown). The lower end of the shell 2 has an outlet which is normally closed by means of a gas sealing bell 11, for discharging the collected impurities from the chamber C, when necessary or desirable.

v Secured within the cleaner shell 2, at its lower end, is. a clean gas chamber D, this chamber having a side wall 12 and frustoconical ends 13 and 14. The chamber D is supported by a series of brackets 2 and 12 from the outer shell 2 and has a tubular neck 15 which extends upwardly through the partition 8 and head 5, and connects the chamber D and insulator chamber A. The relative diameter of the cylindrical shell 2 and wall 12 of the chamber D is such as will provide-an annular space 16 connecting the upper and lower ends of the impurity collecting chamber C, this space 16 permitting free passage of the separated impurities to the bottoni'of the chamber C. The lower end of the gas collecting chamber D has an outlet through which any impurities accumulated therein are discharged at. intervals into the impurity collecting chamber C, a gas sealing bell 17 normally closing the outlet in the bottom of the clean gas chamber D. This bell and also the bell 11 will be equipped with a suitable operating mechanism, which being an old and well-known construction, is not shown nor further described.

A clean gas conduit 18 extends through the side walls 2 and 12 of the chambers C and D, and has a downwardly turned elbow 19 on its inner end which forms an outlet through which the cleaned gases flow from the clean'gas chamber D into the clean gas main 18 which conducts the gases to a place of use.

Secured at their upper ends in suitable openings in the partition 8 so as to depend vertically, is aseries of short pipes or conduits 20, these tubes being arranged in concentric rows and forming tubular grounded electrodes (as is shown in Fig. 2). Also extending through openings or holes in the frusto-conical upper end 13 of the clean gas chamber D is a similar series of short lengthwise vertical pipes or conduits 21, forming a lower series of grounded electrodes. The tubular electrodes 21, which are of somewhat smaller diameter than the trodes 20 and coact therewith to form annular passages or outlets 22 through which separated impurities pass into the impurity collecting chamber C, as will be explained in detail hereinafter. The ipes or tubular electrodes 20, 21 are rigidly fastened in axial alinement with the ends thereof overlapping in the manner shown in Figs. 1 and 3.

Positioned; within the upper end of each of the depending pipesor tubular electrodes 20 is a centrifugal header 23, (see Figs. 1 and 3) having lugs 23 thereon to position and hold the headers in place within the pipe electrodes 20. Each of the headers 23 is provided on its periphery with a series of curved 'vanes 24:, which are arranged to form curved passages and to impart a rapid helical whirling motion to the annular column of gases passed therethrough, the vanes converging downwardly, as is best seen in the development shown in Fig. 7, and having the curved portions thereof tangent with straight portions 25, the straight portions'25 Iforming parallel sided outlets :26 opening into the tubular electrodes 20.

(See Fig. 7;) Also positioned within each of the pipes is anupwardly extending discharge electrode 27, the electrodes being preferably of substantial cross section and having threaded upper ends projecting upwardly into the lower end of the depending tubular the threads may be rounded.' -When desired,

however, the upper end of the electrodesmay be provided with a series of parallel peripheral ridges or collars 30 formed as shown in Fig. 6, or they may be formed by twisting metal bars of rectangular cross section, and in some cases a cylindrical wire or rod having a plane surface may be used.

The electrodes 27 are rigidly fastened at their lower ends to a bottom spider 31, which is fastened to the lower end of a support 32, which, as shown, is tubular, the support extending upwardly through the tubular neck 15 of the chamber 1) into the insulator chamber A. The support 32 may be fluted or corrugated in cross section or may be formed of a plurality of spaced parallel rods instead of being tubular as shown. The upper end of the support 32 also is provided with a spider 33, and the outer ends of the arms of this spider are adjustably supported upon insulators 34 within the insulator chamber A. Adjusting screws 35 on the arms of the upper spider 33 provide a convenient means for adjusting the spiders and series of upwardly extending discharge electrodes 27 on the lower spider 31 axially with regard to the tubular grounded electrodes 20, 21 of the apparatus.

An inlet insulator 36 is provided on the top of the insulated chamber A throu h which the spiders and discharge electro es are connected by a wire or lead 37 to a source of high tension electric current. The shell 2 of the apparatus will be grounded so that when current is supplied through the 3 lead to the discharge electrodes 27 within the tubular grounded electrodes, a corona discharge will be maintained across the ap between the dischar e and grounded e ectrodes through whic the columns of gases pass from the chamber B' into the chamber D, and to some extent the chamber C.

The lower end of the impurity collecting chamber C is connected by a pipe 38 and branch pipe 39 to the annular gas conduit 10 in order to create a slight circulation of gases through the chamber C, and thereby facilitate the de osition of impurities in the chamber C. X fan 40 driven by a motor 41 is connected to the pipe 38 so as to insure the circulation travehng through the pipe 38 from the lower end of the impurity collecting chamber C to the annular gas conduit 10 and gas distributing chamber B. The upper end of the pipe 38 opens into the atmosphere and valves 42 and 43 control the net/2,710

direction of flow of the gases through the pipe 38 into the conduit 10 or into the atmosphere, as is found necessary or desirable.

In using our improved method of cleaning gases, a high tension current at a sufficiently high voltage will be supplied through the lead 3?. spiders 31 and 33, and spider support 32, to the discharge electrodes 27, and. Y in this way a corona discharge will be caused to pass from the discharge electrodes 27 to the walls of the tubular-grounded electrodes 20.

The impurity laden gases will be delivered into the gas receiving chamber B through the branch inlets 9 connecting this chamber with the annular gassupply main 10. The gases pass from the chamber A into the series of conduits or pipes forming the grounded electrodes of our improved apparatus, and are thereby broken up into a series of small streams or columns which pass downwardly through the tubular electrodes 20 and electrode extensions 21.

In entering the tubular grounded elec trodes 20, the gases contact with the spiral vanes 2-1 on the centrifugal headers 23, which are positioned within the upper end ol each grounded electrode 20, and the vanes impart a rapid spiral movement to the flowing gases and form an annular column of gases within each tubular electrode. The spiral whirling movement given the gases by the vanes 2-l causes impurities in the gases to be thrown outwardly and to be held against the surfaces of the tubular electrodes by centrifugal force while the gases, after passing the headers in the upper end of the tubular electrodes, being much lighter than the impurities, are expanded centripetally within the tubular electrodes. In this way each of the columns of gases is formed into a thin annular layer of impurity laden gases and central core of cleaned gases which, in this arrangement, pass through the ionizing zones formed in the tubular electrodes by the corona discharge maintained between the discharge electrodes 23' and inclosing tubular grounded electrodes 20.

The impurities, except the smallest and lightest particles, are concentrated in a thin annular layer against the inner surfaces of the tubular electrodes 20, and the fine, light particles will become ions, partly by impingement upon the threaded part 28 ot the electrodes and partly by collision with other ions and in passing across the electric field between the electrodes 28 and 20 are driven outwardly into the coarser whirling stream of impurities, and are carried along with the stream into the chamber C."

' The rapid spiral whirling movement or the annular layer of impurity laden gases in each tubular electrode also has a strong scouring effect on thesurfaces of these electrodes which prevents the deposition of imdeposition-of impurities within the chamber tion by bringing a much larger surface of gases.

purities on the surfaces of the grounded electrodes and keeps the surfaces bright and clean.

As the columns of gases continue their passage through-the tubular electrodes the annular layer of heavily laden impurity containing gases passes downwardly through the gap or annular outlet 22 formed between the overlapping ends of the upper and lower tubular electrodes 20 and 21 into the impurity collecting chamber C, and the impurities become deposited inthe bottom of this chamber. The central cores of cleaned gases pass downwardly through the tubular electrode extensions 21 intothe cleaned gas chamber D, and pass from this chamber to a place of use through the clean gas outlet 18.

Any impurities which collect in the lower part of the chambers C- and D are removed from time to time by lifting the gas sealing bells 11 and 17., the impurities being discharged by gravity.

' Tn order to maintain acirculation of gases in the impurity collecting chamber C, one or the other of the valves 42 and 43 will be opened and the fan 40 will be driven by the motor 41, and in this way back pressure in the chamber C will be prevented and the C will be facilitated.

The advantages of our invention will be apparent to those skilled in the art. llZ y the use of our improved method and apparatus a stream of impurity laden gases is mechanically broken up into a series of smaller annular columns at the commence ment of the cleaning operation, which increases the eliiciency oi the cleaning opera- Mltl the gases intorontact' with the cleaning mediums. Tn forming the annular streams of gases a rapid spiral or whirling motion is imparted to each stream so as to centrifugally form and hold the impurities in the no gases in a thin annular layer whilepermitting the bullr or major portion of the gases to freely expand centripetally into a central core of cleaned gases. Theso formed gas columns comprising a large central core of cleaned gases and thin surrounding layer of ,helically traveling impurity laden gases itacilitates the completion of the cleaning operation by means of the'corona'discharge occurring within the grounded electrode. 12a The combined mechanical and electrical action employed in cleaning gases by our im proved method enables the length of the electrified or ionizing zone through which the gases must be passed in order to be etlecr25 tively cleaned, to be made very short instead of being many feet in length, as is necessary in the methods and apparatus heretofore used in electrically cleaning Many modifications in the construction and arrangement of the apparatus used 1n carr in out our invention ma be made without departingfrom the invention as defined in the appended claims, We are the first, in so far as we are aware, to employ a combination of centrifugal and electrical forces in cleaning gases and we intend to cover such feature broadly.

We claim 1. The method of cleaning gases which consists in passing a column of gases through a hollow electrode, imparting a whirling movement to the column of gases within the electrode to centrifugally throw impurities therein to the periphery of the column, maintaining a corona discharge within said electrode traversed by the column of gases to ionize and impel impurities in the gases to the periphery of the column of gases and conducting the central core of cleaned gases and surrounding layer of impurity laden gases into separate clean gas and impurity collecting chambers.

2. The method of cleaning gases which consists in separating a stream of gases into a plurality of smaller columns, passing the separate gas columns through hollow, imperforate electrodes, maintaining a corona discharge within said electrodes traversed by said gaseous columns to ionize and impel impurities in the gases to the periphery of the gaseous columns and collecting the central core of cleaned gases and surroundin layer of impurity laden gases in said co umns in separate clean gas and impurity collecting chambers.

3. The method of cleaning gases which consists in separating a stream of gases into a plurality of smaller columns, passing the columns of gases through hollowelectrodes,

imparting a whirling movement to the gaseous columns within the electrodes to centrifugally throw impurities therein to the periphery of the columns, maintaining a corona discharge within said electrodes traversed by said gaseous columns to ionize and impel impurities in the gases to the periphery of the gaseous columns and'collecting the central core of cleaned gases and surrounding layer of impurity laden gases in said columns in separate clean gas and impurity collecting chambers.

4. The method "of cleaning gases which consists in imparting a rotary whirling motion to an annular stream of gases to hold contained impurities centrifugally on the periphery of the gaseous stream while expandlng the gases centripetally into a central-core of cleaned gases, passing the gases through a corona discharge to ionize and complete the removal of impurities from the expanded gases tothe periphery of the stream, and conducting the \central core of cleaned gases and peripheral layer of impurity laden gases into separate clean gas and impurity collecting chambers.

5. The method of cleaning gases which consists in imparting a whirling motion to an annular stream of gases to centrifugally hold contained impurities on the periphery of the gaseous stream, passing the gases through a corona discharge to ionize and complete the removal of impurities from the gases to the periphery of the column, and conducting the central core of cleaned gases into a gas collecting chamber and peripheral layer of impurity laden gases into an impurity collecting chamber.

6. The 'method of cleaning gases which consists in imparting a whirling motion to a flowing stream of gases to maintain the impurities centrifugally on the periphery of the column of gases, passing the whirling gases through a corona discharge to complete the removal of impurities to the periphery of the gaseous column, mechanically separating the core of cleaned gases 7 from the peripheral layer of impurity laden gases, and conducting the central core of 7. The method of cleaning gases which consists in imparting a whirling motion to.

a flowing stream of gases to throw the impurities centrifugally to the periphery of the gas column while expanding the gases centripetally into a core of cleaned gases, passing the whirling gases through an electrical field to complete the removal of impurities to the periphery of the gaseous stream, mechanically separating the core of cleaned gases from the peripheral layer of impurity laden gases, and conducting the central core of cleaned gases, and peripheral layer of impurity laden gases into separate receiving chambers.

8. The method of cleaning gases which consists in imparting a whirling motion to a flowing stream of gases to throw contained impurities centrifugally to the periphery of the column of gases while expanding the gases centripetally into a central core of cleaned gases and then passing the gases through an electric field having a corona discharge to ionize and thereby complete the removal of impurities to the periphery of the gaseous column, mechanically separating the core of cleaned gases from the peripheral layer of impurity laden gases, conducting the central core of cleaned gases into a gas collecting chamber and peripheral layer of impurity laden gases into an impurity collecting chamber, and separating v the impurities and impurity laden gases, by deposition, in the impurity collecting chamber.

9. Apparatus for cleaning gases comprising a hollow electrode having a gas inlet adjacent to one and a clean gas outlet adjacent to its opposite end, means for maintaining a corona discharge within the electrode to thereby create an electric ionizing field travlet adjacent to one and a clean gas outlet.

adjacent to its opposite end, means for maintaining a corona discharge withintheelectrode to thereby create an electric ionizing field traversed by gases passing through the electrode, means at the inlet end of said electrode for imparting a whirling movement to gases entering the electrode, tothereby centrifugally separate the gaseous stream into an inner core of cleaned gases and surrounding layer of impurity laden gases, and a discharge outlet on the periphery of said hollow electrode at an intermediate point in the length thereof through which the layer of impurity laden gases passes to thereby separate the impurities from the cleaned gases.

11. Apparatus for cleaning gases comprising a hollow electrode havlng a gas inlet adjacent to one and a clean gas outlet adjacent to its opposite end, a header having spiral vanes on the periphery thereof at the inlet end of said electrode for imparting a v whirling movement to entering gases to thereby centrifugally separate the gaseous v stream into an inner core of cleaned gases and surrounding layer of mpurity laden gases, means for ma ntaming a corona discharge within the electrode to thereby create an electric ionizing field traversed by gases passing through the electrode and ionize in'1- purities in the gases, and an impurity discharge outlet on the periphery of the hollow electrode through which thelayer of impurity laden gases passes to thereby separate the impurities from the cleaned gases.

12. Apparatus for cleaning gases comprising. a gas distributing chamber, a plurality of hollow electigodes connecting the distributing chamber with the collecting chamber, means for maintaining a corona discharge within the hollow electrode to thereby create an electric ionizing field traversed by the gases passed through the electrode, means at the inlet end of said electrodes for imparting a whirling movement to the gases entering the electrode to thereby centrifugally separate the gaseous streams into an innercore ofcleaned gases and 'sur-' rounding layer of impurity laden gases, and

a discharge outleton the periphery of said hollow electrode through which the layer of impurity laden gases passes to thereby separate the impurities from the cleaned gases. v

13. Apparatus for cleaning gases comprising a gas distributing chamber, a gas collecting chamber; a. plurality of hollow electrodes connecting the distributing chamber with the collecting chamber, means for maintaining a corona discharge within the hollow electrode to thereby create an electric ionizing field traversed by the gases passed through the electrode, means at the inlet end of said electrodes for forming the entering gases into annular helically whirl ing streams to thereby centrifugally maintain contained impurities on the periphery of the gaseous columns while centripetally expanding the gases, and a discharge outlet on the periphery'of said hollow electrode through which the layer of impurity laden gases passes tothereby separate the impurities from the'cleaned gases.

In witness whereof, we have hereunto signed. our names.

' FRANK JR. MoGElE.

ARTHUR F. NESBIT. 

